Semi-tractor

The fleet has 48 semi-tractors and 164 trailers that transport 110,000 tons of parts and supplies annually over 1 million miles of roads.

Some people think diesel fuel is only used in semi-tractors (Figure 9.3) or heavy equipment.

Security seal use applies when carrying merchandise in semi-truck trailers (highway trailers) pulled by semi-tractors and when railroad flatcars carry the trailers, the latter referred to as piggyback (piggybacking).